This invention relates generally to the testing of cables and wire harnesses, and more particularly concerns a novel tester apparatus that is expansible, as in modular mode or modes, to accommodate testing of different size wire harnesses, or multiple connectors on wire harnesses.
Cable testers are used to verify electrical specifications of conductors in cable and wire harnesses, as for example circuit continuity. In the past, different size testers were required in order to test different size wire harnesses.
Typically, a circuit tester apparatus tests an electric circuit by testing the electrical connections between all of the electrical points in that circuit. The tester apparatus includes elements called xe2x80x9ctest pointsxe2x80x9d that are electrically connected to the electrical points in the circuit while the circuit is being tested. Typically, the tester apparatus includes one test point for each point in the circuit that is being tested, and so the number of test points in the tester apparatus must equal or exceed the number of points in the circuit being tested. A circuit with a large number of points can be tested only by a tester apparatus that has an equally large number of test points. Since one of the most expensive components of a tester apparatus is its test point circuitry, the cost of a tester apparatus is directly related to its number of test points.
Prior art tester apparatus uses carrier elements to which the circuit points of a cable or wire harness are electrically connected in order to be tested. The carrier elements include first electrical connectors which comprise terminal pins, and the tester apparatus includes second electrical connectors which comprise terminal pin receptacles. The carrier elements are interfaced to the second electrical connectors by interfitting the first electrical connectors to the second electrical connectors.
In prior art apparatus, it is acceptable for the number of circuit points to which an individual carrier element is connected to be less than the number of receptacles in the second electrical connector to which that carrier element is interfaced. However, in this situation, some of the receptacles in that second electrical connector are not utilized, and, as a result, some of the test points that are assigned to that particular second electrical connector are not utilized. This means that some of the test point capacity in the testing apparatus is wasted.
If such prior art tester apparatus is configured to include multiple carrier elements, and if the maximum number of circuit points to which each carrier element can be connected is less than the number of receptacles in each second electrical connector, then a certain number of the test points associated with each second electrical connector is wasted. As a result, because each test point in the tester apparatus is assigned to a specific second electrical connector, and because the tester apparatus must include one second electrical connector for each carrier element, it is necessary for the tester apparatus to have a total number of test points that is significantly greater than the number of points in the circuit being tested. This means that a significant proportion of the test point capacity of the tester apparatus is wasted, and the cost of the tester apparatus is higher than it would be if the number of test points were limited to the number of points in the circuit being tested.
There is continuing need for simple, low-cost, tester apparatus that can readily interface to different size wire harnesses, and to multiple connectors to be simultaneously tested. This invention improves upon the tester apparatus disclosure in U.S. Pat. No. 5,072,185 to Rockwell.
It is a major object of the invention to provide improved interface and tester apparatus meeting the above needs. Basically, the apparatus of the invention is useful in testing electrical cables or wire harnesses. One or more carrier elements, such as adapter cards, are employed, having first electrical connectors, and the apparatus in one form comprises:
a) multiple base sections connected in end to end longitudinal sequence,
b) and second electrical connectors carried by said sections and positioned to interfit said first electrical connectors when said element or elements are assembled to said multiple sections.
As will be seen, connectorized adapter cards of different sizes, or two or more of the connectorized adapter cards, can be accommodated, as by bridging one or more of the sections assembled together in end-to-end relation. Two or more adapter cards can also be accommodated in a single section depending on the size of the adapters. In this regard, the second electrical connectors carried by end-to-end sections are in generally longitudinal alignment, to provide modularity.
It is another object of the invention to locate the second electrical connectors in two laterally spaced rows, the connectors in each row being in generally longitudinal alignment successively of said sections. One row of the second electrical connectors is also contemplated, as will appear.
Yet another object is to provide second electrical connectors in the form of receptacles configured to receive the first connectors. Such first connectors typically comprise terminal pins carried by the circuit board or boards that may or may not overlap or bridge successive sections. Such circuit boards are also referred to herein as adapter cards, and vice versa. Alternatively, the first electrical connectors may comprise receptacles carried by the adapter card or cards, and the second electrical connectors may comprise terminal pins receivable by receptacles.
A further object is to provide simple, plug-in type end-to-end connection of successive sections, for ready expansion of the tester apparatus. Alignment plates may be employed proximate plug-in connectors to aid in preventing mis-alignment of successive expansion sections, as in a row.
The method of employing circuit tester apparatus for testing wire harnesses via first electrical connectors, on one or more carrier elements such as adapter cards, includes the steps:
a) providing a base section or sections to which one or more adapter cards may be assembled,
b) and providing second electrical connectors carried by said section or sections and positioned to interfit the first electrical connectors when the card or cards are assembled to the section or sections, at least one of such second electrical connectors configured to interfit, simultaneously, at least two of the first electrical connectors.
The method may also include adding a second of said sections to, and endwise of, a first of said sections, and employing at least one of the adapter cards associated with the cards and sections to interconnect first and second electrical connectors.
Testing via the board or card circuitry is carried out after the boards are applied, as referred to.
In the present invention, each second electrical connector is configured as a continuous connector that can be interfitted simultaneously to multiple first electrical connectors. This allows multiple first electrical connectors, of either the same size or of different sizes, to be xe2x80x9cstackedxe2x80x9d, end-to-end, onto a single second electrical connector. Accordingly, multiple carrier elements, of either the same size or of different sizes, can be interfaced simultaneously to a single second electrical connector.
Multiple base sections can be connected in end-to-end longitudinal sequence, in which case the row or rows of second electrical connectors on the multiple sections are aligned longitudinally, and each row of second electrical connectors on the multiple sections becomes a single, extending, continuous connector that runs the length of the successive sections and can be interfitted simultaneously to numerous first electrical connectors or can be interfitted to a single first electrical connector that has a quantity of terminal pins that is greater than the quantity of receptacles in any one of the aligned second electrical connectors.
In addition, two successive second electrical connectors that extend as one continuous connector can be interfitted simultaneously to one first electrical connector, so that the one first electrical connector overlaps or bridges the two second electrical connectors. This can be achieved with several different configurations of the tester apparatus. In one configuration, the two second electrical connectors are longitudinally aligned connectors that are included in the same base section. In another configuration, there are two base sections connected in end-to-end longitudinal sequence, and one of the second electrical connectors is included in the first base section and the other second electrical connector is included in the second, successive base section. In both configurations, the number of pins in the first electrical connector can be greater or less than the number of receptacles in each second electrical connector.
The following are examples of various configurations of the invention in which the number of second electrical connectors is different from the number of carrier elements:
If the tester apparatus includes three carrier elements (A, B, and C), and if the maximum number of circuit points to which each carrier element can be connected is less than one third of the number of receptacles in a single second electrical connector (AA), then all three carrier elements A, B, and C can be interfaced simultaneously to the single second electrical connector AA.
If the tester apparatus includes three carrier elements (A, B, and C), and if the number of circuit points to which each of carrier elements A, B, and C can be connected is less than two thirds of the number of receptacles in each of two successive second electrical connectors (AA and BB), then all three carrier elements A, B, and C can be interfaced simultaneously to the two second connectors AA and BB, with carrier element A interfaced to second connector AA, carrier element B overlapping both second connectors AA and BB and interfaced to both, and carrier element C interfaced to second connector BB. The two second connectors AA and BB can be successive connectors that are included in the same base section, or, if there are two base sections connected in end-to-end longitudinal sequence, then second connector AA can be included in the first base section and second connector BB can be included in the second section.
If the tester apparatus includes one carrier element (A), and if the number of circuit points to which carrier element A is to be connected exceeds the number of receptacles in each second electrical connector, then carrier element A can be interfaced simultaneously to multiple, aligned second electrical connectors, as long as the total number of receptacles in all of the aligned second electrical connectors equals or exceeds the total number of circuit points to which carrier element (A) is to be connected.
The present invention provides numerous benefits over circuit testers in the prior art. These benefits include:
In this invention, the number of carrier elements can exceed the number of second electrical connectors, and vice versa.
In this invention, the maximum number of circuit points to which a carrier element can be connected can be less than the number of receptacles in the second electrical connector to which that carrier element is interfaced, without causing a certain number of the test points associated with that second electrical connector to be wasted.
By configuring the second connector as a continuous connector, so that multiple carrier elements can be interfaced simultaneously to each second electrical connector, this invention allows the use of multiple carrier elements and multiple second electrical connectors without requiring that a certain number receptacles in each second electrical connector (and thus a certain number of test points) be wasted. Even in cases in which the maximum number of circuit points to which each carrier element can be connected is less than the number of receptacles in each second electrical connector, this invention does not require that a certain number of the test points associated with each second electrical connector be wasted.
The maximum required test point capacity of the tester apparatus can be limited to approximately the number of points in the circuit being tested.